- ID:
- ivo://CDS.VizieR/J/A+A/324/1059
- Title:
- C-rich stars IR and UBVRI photometry
- Short Name:
- J/A+A/324/1059
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A study of circumstellar dust shells (CDS) around carbon stars is presented. This study is based on the analysis of the 1-100{mu}m broad-band spectra of 23 objects which have been monitored in the 1-20{mu}m region over several years at ESO. The sources in the sample range from Irr/SR variables and optical Miras to Extreme Carbon Stars which have only been discovered recently in infrared surveys. A modelling accounting for the photometric variations with phase (with up to 9 spectra per object) has been developed. All the CDSs in the sample can be modelled successfully in spherical geometry with a dust opacity law {prop.to}{lambda}^-1.3^ and a dust formation temperature ~950K. The modelling favors the case of an acceleration of dust, from the site of formation and on a distance of ~10^15^cm, over the case of a uniform expansion. Mass loss rates in the range 0.1-50x10^-6^M_{sun}_/yr are derived. The estimates based on this modelling are consistent with those derived from the CO emission line measurements. In view of the incoming near-infrared surveys (DENIS and 2MASS), an analysis of the location of carbon-rich sources in color diagrams is presented. It is shown that the near-infrared colors are well correlated with the mass loss rate. This property can be used to get an estimate, within a factor 3, of this rate for carbon stars without a priori on the distance.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/658/345
- Title:
- CRIc photometry of Magellanic Bridge Fields
- Short Name:
- J/ApJ/658/345
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report on observations of the stellar populations in 12 fields spanning the region between the Magellanic Clouds, made with the Mosaic II camera on the 4m telescope at the Cerro-Tololo Inter-American Observatory. The two main goals of the observations are to characterize the young stellar population (which presumably formed in situ in the Bridge and therefore represents the nearest stellar population formed from tidal debris), and to search for an older stellar component (which would have been stripped from either Cloud as stars, by the same tidal forces that formed the gaseous Bridge). We determine the star formation history of the young inter-Cloud population, which provides a constraint on the timing of the gravitational interaction that formed the Bridge. We do not detect an older stellar population belonging to the Bridge in any of our fields, implying that the material that was stripped from the Clouds to form the Magellanic Bridge was very nearly a pure gas.
- ID:
- ivo://CDS.VizieR/J/ApJ/776/L20
- Title:
- C/2012 S1 (comet ISON) R photometry
- Short Name:
- J/ApJ/776/L20
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report photometric observations for comet C/2012 S1 (ISON) obtained during the time period immediately after discovery (r=6.28AU) until it moved into solar conjunction in mid-2013 June using the UH2.2m, and Gemini North 8m telescopes on Mauna Kea, the Lowell 1.8m in Flagstaff, the Calar Alto 1.2m telescope in Spain, the VYSOS-5 telescopes on Mauna Loa Hawaii and data from the CARA network. Additional pre-discovery data from the Pan STARRS1 survey extends the light curve back to 2011 September 30 (r=9.4AU). The images showed a similar tail morphology due to small micron sized particles throughout 2013. Observations at submillimeter wavelengths using the James Clerk Maxwell Telescope on 15 nights between 2013 March 9 (r=4.52AU) and June 16 (r=3.35AU) were used to search for CO and HCN rotation lines. No gas was detected, with upper limits for CO ranging between 3.5-4.5x10^27^molecules/s. Combined with published water production rate estimates we have generated ice sublimation models consistent with the photometric light curve. The inbound light curve is likely controlled by sublimation of CO_2_. At these distances water is not a strong contributor to the outgassing. We also infer that there was a long slow outburst of activity beginning in late 2011 peaking in mid-2013 January (r~5AU) at which point the activity decreased again through 2013 June. We suggest that this outburst was driven by CO injecting large water ice grains into the coma. Observations as the comet came out of solar conjunction seem to confirm our models.
- ID:
- ivo://CDS.VizieR/J/ApJ/900/140
- Title:
- CSP-II: sp. obs. of the 03fg-like SN Ia LSQ14fmg
- Short Name:
- J/ApJ/900/140
- Date:
- 02 Feb 2022 11:26:50
- Publisher:
- CDS
- Description:
- The Type Ia supernova (SN Ia) LSQ14fmg exhibits exaggerated properties that may help to reveal the origin of the "super-Chandrasekhar" (or 03fg-like) group. The optical spectrum is typical of a 03fg-like SNIa, but the light curves are unlike those of any SNe Ia observed. The light curves of LSQ14fmg rise extremely slowly. At -23 rest-frame days relative to B-band maximum, LSQ14fmg is already brighter than M_V_=-19mag before host extinction correction. The observed color curves show a flat evolution from the earliest observation to approximately 1 week after maximum. The near-infrared light curves peak brighter than -20.5mag in the J and H bands, far more luminous than any 03fg-like SNe Ia with near-infrared observations. At 1 month past maximum, the optical light curves decline rapidly. The early, slow rise and flat color evolution are interpreted to result from an additional excess flux from a power source other than the radioactive decay of the synthesized 56Ni. The excess flux matches the interaction with a typical superwind of an asymptotic giant branch (AGB) star in density structure, mass-loss rate, and duration. The rapid decline starting at around 1 month past B-band maximum may be an indication of rapid cooling by active carbon monoxide (CO) formation, which requires a low-temperature and high-density environment. These peculiarities point to an AGB progenitor near the end of its evolution and the core degenerate scenario as the likely explosion mechanism for LSQ14fmg.
- ID:
- ivo://CDS.VizieR/J/A+A/609/A134
- Title:
- CSP-I photometry for 34 supernovae
- Short Name:
- J/A+A/609/A134
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The first phase of the Carnegie Supernova Project (CSP-I) was a dedicated supernova follow-up program based at the Las Campanas Observatory that collected science data of young, low-redshift supernovae between 2004 and 2009. Presented in this paper is the CSP-I photometric data release of low-redshift stripped-envelope core-collapse supernovae. The data consist of optical (uBgV ri) photometry of 34 objects, with a subset of 26 having near-infrared (YJH) photometry. Twenty objects have optical pre-maximum coverage with a subset of 12 beginning at least five days prior to the epoch of B-band maximum brightness. In the near-infrared, 17 objects have pre-maximum observations with a subset of 14 beginning at least five days prior to the epoch of J-band maximum brightness. Analysis of this photometric data release is presented in companion papers focusing on techniques to estimate host-galaxy extinction (Stritzinger et al., submitted) and the light-curve and progenitor star properties of the sample (Taddia et al., submitted). The analysis of an accompanying visual-wavelength spectroscopy sample of ~150 spectra will be the subject of a future paper.
1466. CSS21055 light curves
- ID:
- ivo://CDS.VizieR/J/A+A/558/A96
- Title:
- CSS21055 light curves
- Short Name:
- J/A+A/558/A96
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report photometric observations of the eclipsing close binary CSS21055 (SDSS J141126+200911) that strongly suggest that the companion to the carbon-oxygen white dwarf is a brown dwarf with a mass between 0.030 and 0.074M_{sun}. The measured orbital period is 121.73-min and the totality of the eclipse lasts 125s. If confirmed, CSS21055 would be the first detached eclipsing WD+BD binary. Spectroscopy in the eclipse could provide information about the companion's evolutionary state and atmospheric structure.
- ID:
- ivo://CDS.VizieR/J/MNRAS/469/3688
- Title:
- CSS Periodic Variable Star Catalogue
- Short Name:
- J/MNRAS/469/3688
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Here we present the results from our analysis of six years of optical photometry taken by the Siding Spring Survey (SSS). This completes a search for periodic variable stars within the 30,000 square degrees of the sky covered by the Catalina Surveys. The current analysis covers 81 million sources with declinations between -20 and -75 degrees with median magnitudes in the range 11<V<19.5. We find approximately 34,000 new periodic variable stars in addition to the ~9,000 RR Lyrae that we previously discovered in SSS data. This brings the total number of periodic variables identified in Catalina data to ~110,000. The new SSS periodic variable stars mainly consist of eclipsing binaries, RR Lyrae, LPVs, RS CVn stars, {delta} Scutis and Anomalous Cepheids. By cross-matching these variable stars with those from prior surveys, we find that ~90% of the sources are new discoveries and recover ~95% of the known periodic variables in the survey region. For the known sources, we find excellent agreement between our catalogue and prior values of luminosity, period and amplitude. However, we find many variable stars that had previously been misclassified. Examining the distribution of RR Lyrae, we find a population associated with the Large Magellanic Cloud (LMC) that extends more than 20 degrees from its center confirming recent evidence for the existence of a very extended stellar halo in the LMC. By combining SSS photometry with Dark Energy Survey data, we identify additional LMC halo RR Lyrae, thus confirming the significance of the population.
- ID:
- ivo://CDS.VizieR/J/AJ/123/832
- Title:
- C star population in NGC 6822
- Short Name:
- J/AJ/123/832
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using the CFH12K camera, we apply the four-band photometric technique to identify 904 carbon stars in an area 28'x42' centered on NGC 6822. A few C stars outside of this area were also discovered with the Las Campanas Swope Telescope. The NGC 6822 survey employs two sets of observations obtained by rather different telescopes and with different procedures: the Swope Telescope on Las Campanas was used in 1999 October to secure images of NGC 6822 in Kron-Cousins R_KC_, CN (810nm), and TiO (770nm) filters. The 2048x2048 SITe No. 1 CCD yields a field of view of 23.7'x23.7'; NGC 6822 was also observed with the CFH12K at the beginning of one night in 2000 September. The camera consists of a 12Kx8K pixel mosaic covering a field of 42'x28', with each pixel corresponding to 0.206". Images were obtained through Mould I and R filters and through the CN and TiO filters. The NGC 6822 C star population has <I>=19.26 leading to an <M_I_>=-4.70, value essentially identical to the mean magnitude obtained for the C stars in IC 1613. Contrary to stars highlighting the optical image of NGC 6822, C stars are seen at large radial distances and trace a huge, slightly elliptical halo, which does not coincide with the huge H I cloud surrounding NGC 6822. The previously unknown stellar component of NGC 6822 has a exponential scale length of 3.0+/-0.1' and can be traced to 5 scale lengths. The C/M ratio of NGC 6822 is evaluated to be 1.0+/-0.2.
- ID:
- ivo://CDS.VizieR/J/A+A/436/91
- Title:
- C star population in outer disk of M31
- Short Name:
- J/A+A/436/91
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We employ the CFHT Megacam camera to survey ~1{deg}^2^ of the southern outer disc of M31, a region which includes the area where Battinelli et al. (2003, Cat. <J/AJ/125/1298>) have identified nearly one thousand C stars. In the outer M31 region not previously surveyed, we identify 361 new C star candidates, having similar photometric properties to the known ones, and confirm the slight decrease in the luminosity of C stars with galactocentric distances. We show that the Sloan g', r', i' filters are a viable approach, comparable to (CN-TiO), to identify C stars. We find that the (g'-r') colours of cool C stars can be so red that prohibitively long g' exposures are needed to acquire faint extragalactic C stars. This makes the Sloan filters a less promising approach to extend a C star survey to several Mpc. Our uniform large field survey detects the edge of M31 disk at ~35kpc. The intermediate-age population, represented by C stars, extends further to ~40kpc.
- ID:
- ivo://CDS.VizieR/J/AJ/125/1298
- Title:
- C star population in outer disk of M31
- Short Name:
- J/AJ/125/1298
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We employ the CFH12K mosaic to identify carbon stars, using the R, I, CN, and TiO photometric technique, in a 2240 arcmin2 area, ranging from 17 to 30kpc of the southwest disk of M31, barely reaching the edge of the observed H I disk. We found 945 C stars with <I_0_>=19.94mag and {sigma}=0.47. The surface density of C stars along the major axis of M31 follows an exponential profile with a scale length of 4.85+/-0.35kpc, in agreement with adopted values for the scale length of the disk population. Our survey partially overlaps with the recently discovered G1 density enhancement by Ferguson et al. We confirm that no AGB star excess is detectable in the surveyed part of the clump. The C/M ratio, along the major axis, is derived over a distance range of 7kpc. The strong C/M gradient seen contrasts with results of previous studies of the C stars in M31.
